Many children and youth with physical disabilities have motor coordination problems that make it difficult to walk without support. Children, who can bear weight through their legs and feet, but lack the strength or motor coordination to use canes or crutches either rely on stationary walkers (walkers without wheels), or wheeled walkers to ambulate. Children's walkers increase standing and walking stability, improve functional mobility, and reduce the likelihood of falls. These commonly used assistive technology devices help children to participate more fully in daily living activities at home; at school, and in the community.
Although adults and seniors with balance problems or unsteady gait tend to use wheeled walkers that they push as they walk; children with neurodevelopmental disabilities, such as cerebral palsy, walk much better when they use a walker that they pull as they walk. These types of walkers are called reverse or posterior walkers. See, for example, U.S. Pat. No. 6,311,708. Posterior placement of the walker is generally preferred to anterior placement because this orientation allows children to walk more upright, have better control while walking, and improve their access to doors, tables, and other objects.
Examples of commercially available posterior walkers include Kaye™ posture control walkers (Kaye Products, Inc., Hillsborough, N.C.), the Nurmi Neo™ walking aid (Otto Bock HealthCare, Minneapolis, Minn.) and the Crocodile™ gait trainer (Snug Seat, Inc., Matthews, N.C.).
Existing posterior walkers are typically tubular frames configured to extend from the ground to the level of the child's hips. The frame surrounds the child on three sides, but is displaced outwardly from the body to provide the child unhindered movement within the frame during gait. The frame typically contacts the ground at three or four points to provide enhanced lateral, forward and backward stability for the child. The frame contacts the ground via rubber tips and/or wheels. A child who is very unsteady and unable to control a wheeled walker normally requires rubber tipped ends; whereas, a child who has greater dynamic balance obtains greater mobility using a frame with two, three, or four wheels.
Wheeled walkers commonly have two waist-high handles that children can grip with their hands, or their hands and forearms. The handles allow children to pull and steer the walker as they walk. To customize the handle height for different sizes of children, the handles may be configured to adjust in height with, or relative to; the frame of the walker. Current walkers also have options that allow handles to be adjusted in depth and width to optimize the positioning of the child within the walker.
Posterior wheeled walkers are available in a range of sizes and have accessories that may be added to change the rolling resistance of wheels or prevent them from rotating rearward. These features are useful for children who either are unable to control walkers that have free-rotating wheels, or frequently lose balance because they lack the motor coordination to provide compensatory backward step if the walker moves rearward.
Adjustments made to a walker to accommodate a larger child, or one who has outgrown the walker's current setting, have very little effect on its stability (i.e. its resistance to tipping). Increasing the distances between the ground contact points increases the multidirectional stability of a walker. However, a wider base of support means that the walker is more difficult to direct through doorways, hallways, and in rooms with furniture. Since existing walkers do not have explicit methods for controlling its stability, these devices generally have a fixed base of support and low centre of mass to provide the same level of stability for all children.
In general, children who are unable to walk without support receive a walker when they are between two and three years old. These children take time to learn how to explore their environments with a walker. Therefore, they tend to rely more heavily on a walker for support than older children who are more experienced. As children age, they may bear more weight through their legs, develop improved motor coordination, and become more competent in handling a wheeled walker. To provide greater mobility for the child as s/he becomes a proficient walker user, it would be beneficial to provide a walker that could be adjusted to match its handling to the developmental needs of the child.
In view of the foregoing, a walker with improved stability that helps persons with physical disabilities, unsteady gait or balance problems to walk is desirable.